The Premier League honeymoon is over for Guardiola and Mourinho

Pep Guardiola surely has to deliver the title for Manchester City after such an unprecedented summer of lavish spending. Having gone through a season trophyless for the first time, Guardiola has to prove his sophisticated, complex style will work in England.

The surgery on his squad has been drastic as he looks to find the players who can play the "Pep Way"; City have splashed out approximately £130 million on full-backs alone with the arrivals of Kyle Walker, Benjamin Mendy and Danilo.

Clearly, they've been signed to get forward at every opportunity and augment the threat of a frightening attack that could yet feature Alexis Sanchez, as well as Sergio Aguero and Gabriel Jesus. But will the new full-backs and new goalkeeper Ederson give City the solid look they rarely had last season? There is still that feeling that they need to keep Vincent Kompany fit for that defence to function properly,

However, it might be that City will always score so many goals that the odd mishap at the back will not matter, especially now that they can add Bernardo Silva's creative talents to those of his namesake David, as well as Kevin De Bruyne, Leroy Sane and Raheem Sterling.

It is certainly quite a line up, but with it comes huge weight of expectation and one snag is that the new men do have to be bedded in.

Guardiola's honeymoon period is certainly over and I suspect the same is true for Jose Mourinho at Manchester United, where last season's two trophies rather obscured the fact that United finished a huge -- and rather embarrassing -- 24 points behind champions Chelsea.

It is quite possible that Romelu Lukaku will replace the goals of the absent Zlatan Ibrahimovic but, while useful, will the other signings of Nemanja Matic and Victor Lindelof really make a crucial difference? A dashing wide player like Inter's Ivan Perisic or, dare we say it, Gareth Bale would give United a better balance and thrust.

Lukaku might help United put away some of the lesser lights -- a big problem last year when they drew a league-high 15 games -- but his arrival probably consigns Marcus Rashford to another year out of position on the left wing, rather than marauding through the middle. Mourinho might be right when he says: "We are candidates, but not big candidates."

Jose Mourinho, left, and Pep Guardiola, right, will be expected to challenge for the title.

The last two managers to win the title -- Mourinho and Claudio Ranieri -- have been sacked the following season. It will be a shock if that happens to Chelsea's Antonio Conte, who has signed an improved, though not extended, deal. Things never seem entirely settled at Stamford Bridge, but Conte's excitable desire for success is likely to drive another bold showing.

Having said that, as things stand Chelsea's squad looks a little thin and preseason defending has been less than convincing. Moreover, the early season will be a test with tough games, Eden Hazard still out injured for the first month and the likes of Alvaro Morata and Tiemoue Bakayoko needing time to settle.

Tottenham, who face Chelsea on the second weekend of the campaign, were worthy runners-up last season and the main reason they have not been busy in the transfer market is that they are fairly happy with what they have. Indeed, if they were playing home games at White Hart Lane -- not Wembley -- I would fancy Mauricio Pochettino's men to go very close, if not win the whole thing.

But this group, led by Harry Kane and Dele Alli and with a good defence, have reached the "now or never" stage; they have to claim some silverware. The national stadium has not been a friend to Spurs and, however much they try, it simply is not home and that leaves them needing to improve a patchy away record.

Liverpool have had a good preseason but badly need to keep star man Phillipe Coutinho away from the clutches of Barcelona. Jurgen Klopp's team were exciting to watch in 2016-17, but injuries to Sadio Mane and Jordan Henderson meant they could not sustain a title challenge, though fourth represented progress.

Whether the Reds have the all-round strength to improve on that, as well as handle Champions League involvement, is debatable. So far they have been foiled in attempts to get defender Virgil Van Dijk from Southampton and midfield man Naby Keita from RB Leipzig and much may hinge on whether they can get those deals done in the last weeks of the transfer window.

Arsene Wenger rode through the storm to get a new deal at Arsenal but he is under instructions to build a team to win the title. It's hard to see that happening with only Alexandre Lacazette -- consistently prolific in France -- a significant addition to last year's fitful team, which finished a distant fifth. Losing Sanchez would leave them weaker. In short, Wenger needs to do more.

Everton have been busy in the summer but still need to replace Lukaku's goals. Ronald Koeman's side have lofty ambitions of perhaps making the top four with a revitalised Wayne Rooney, but a repeat of last season's seventh looks more realistic. Elsewhere, West Ham, Leicester and Bournemouth all seem to have done decent business and could go well.

Of the promoted clubs, Newcastle are back but, like promoted Brighton, they need to strengthen further before the window shuts. Huddersfield have been bold and showed they mean business by shelling out big money for Montpellier's prolific striker Stephen Mounie. If he finds form, the Town might just keep themselves up; they are interesting and welcome additions to the division.

Ian Darke, who called games for the network during the 2010 and 2014 World Cups, is ESPN's lead soccer voice in the U.S. Reach him on Twitter @IanDarke.